This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The iron(II) complexes 1a and 2 with pentadentate pyridyl ligands are stable under physiological conditions and exhibit higher cytotoxicities toward a series of human carcinoma cell lines than cisplatin. 1a can significantly increase intracellular oxidant levels, cleave supercoiled plasmidDNA in vitro without addition of a reductant and induce apoptotic cell death in human cervical epithelioid carcinoma cells (HeLa) as observed in flow cytometric studies.